實體的彈起來：紙、帳篷、球
這一支最貼近核心畫面，因為它真的有東西在動：紙立起來、帳篷撐開、球飛上去。先看懂這一支，另外兩支才會覺得理所當然。
adjective · B1
Used in front of book, card and similar words: made so that a folded paper picture stands up off the page by itself when you open it.
立體的（書、卡片）
核心畫面
One picture holds this whole word: something is lying flat and out of sight, and then, with a small noise, it is standing right in front of you. Open a pop-up book and a paper castle rises off the page. Nobody built it; the fold did the work. Every other use is that same moment moved somewhere new — onto a screen, onto a street, into a bag, into the air above a baseball field. Two things always travel with the picture: it arrives by itself, and it was flat a second ago.
整個字可以想成同一個畫面：一樣東西本來平平地折著、看不見，然後「啵」一聲，就立在你面前。翻開一本立體書，紙做的城堡就…更多收起
整個字可以想成同一個畫面：一樣東西本來平平地折著、看不見，然後「啵」一聲，就立在你面前。翻開一本立體書，紙做的城堡就從頁面上升起來。沒有人去組裝它，是折線自己把它撐起來的。其他所有用法，都是同一個瞬間換了場地——換到螢幕上、換到街上、換進行李箱、換到棒球場的上空。這個畫面裡永遠帶著兩件事：它是自己冒出來的，而且一秒之前它還是平的。From the word’s history
Wiktionary records pop-up as deverbal from the phrasal verb pop up — the noun and adjective were simply made out of the verb phrase. That is why every meaning still describes a movement rather than a thing.
字典記載 pop-up 是從動詞片語 pop up 直接轉成名詞和形容詞的（deverbal）。這解釋了為什麼它的每個意思講的都是一個「動作」而不是一種「東西」：不管是紙城堡、彈窗、快閃店還是高飛球，共同點都在它們冒出來的方式。
Wiktionary entries for pop-up (adjective and noun), supplied in this packet: etymology_text 'Deverbal from pop up.' (source_ref kaikki:3f6f69a190036ae4:1009989232 and :1009994271)
Three branches
螢幕上跳出來的東西
同一個瞬間搬進螢幕：原本藏著的東西忽然蓋到你眼前。差別只在於立起來的不是紙，是一層視窗。
noun · B1
A small window that jumps onto your screen on top of what you were looking at — often an advertisement, a warning, or a box asking you to agree to something.
彈出視窗
來得快、收得也快的店
把核心畫面整個搬到街上：一家店像紙城堡一樣忽然立在空店面裡，時間到了又折回去。這裡多了一層時間感——結束日期從一開始就寫在計畫裡。
adjective · B2
Used in front of shop, restaurant, café, store, market and similar words: one that opens in a place for a short, fixed time and then closes again.
快閃的、限時的（店、餐廳）